In general, negative voltage power supplies have been required for the conventional gate drive circuit of the normally-on type GaN-FET. However, the conventional switched-mode power supply (SMPS) and power conversion system have positive voltage power supplies for controlling active power semiconductor switching devices. In this study, a novel gate drive circuit based on positive voltage power supplies for the normally-on type GaN-FET is proposed and discussed. The proposed gate drive circuit is compared with the conventional gate drive circuit using negative voltage power supplies experimentally. Finally, the effectiveness of the proposed circuit is indicated based on the comparative experimental results.